Cloth guider



March A18, 1947.k

J. D. RoBRTsoN cLTH GUIDER Filed nay 17, 1945 4 Shee'ts-Sheet 2 18,1947. J D, ROBERTSQN I 2,417,447

CLOTH GUIDER Filed lay 17, 1945 4 Sheets-Sheet 3 March 1s, 1947.

'.J. D. ROBERTSON CLOTH GUIDER Filed May 17, 1945 4 Sheets-Sheet 4 yPatented Mar. 18,1947

CLOTH GUIDEB John D. Robertson, Taunton, Mass., assigner to Mount `HopeMachinery Company', Taunton, Mau., a corporation of MassachusettsAppuemenmy 11, 194s, serial Ne. 594,325

(ci. ze-s'n 21 Claims.

'I'his inventionrelates to improvementsin cloth guiders and moreparticularly to that class of cloth guiders which are self-acting tocorrect selvage deviations, as distinguished from the relatively morecomplicated and more expensive cloth guiders which require theintervention of an exterior power medium, such as electricity,ycompressed air, and the like, for controlling the selvage correctingmeans.

Cloth guiders of the general type to which the invention relatesordinarily have tiltable pairs Y of rolls which engage opposite selvageregions of a travelling web of cloth, and each pair .of rolls isresponsive automatically to change the degree of tilt of the rollswhenever the engaged selvage region of the web departs from apredetermined transverse relationship to the center-line of travel ofthe web. The respective pairs of rolls are separately tiltable inparallelism with the plane of the web engaged thereby so that atransverse,

traction or repulsion can be exerted by the rolls on the cloth which'traction or repulsion is varied by increase or decrease of the angle oftilt of the rolls relative to a plane at right angles to the plane ofthe travelling web. e

It is among the objects of my present invention to provide atiltable-roll selvage guider embodying features of structural simplicityand sensitivity of operation not possible of attainment in prior selvageguiders of which I am aware. I employ a novel principle of selvagecontrol whereby tilting of the rolls as a result of departure of aselvage from a predetermined course is responsive to frictionalengagement of the selvage with a rotary element which, in one form,continues fixed in its position of rotation regardless of the positionsof the rolls as regards theirdegree of tilt, and which, in another form,moves with the rolls as the latter tilt. l

Another object is to minimize frictional resistance to tilting of thecloth-engaging rolls whereby to attain a superior degree of sensitivityof control-of a selvage. According to the invention a selvage movingoutward between thev rolls As a result, v

2 of a selvage region of web with a drag-increasing portion of a roll oran element or elements carried on the tiltable roll unit.

A further object is to provide means for adjustment of thesewage-engaging means as the diameters of the web-engaging rollsdecrease due to wear. y

Yet another object is to provide adjustable tension means which acts ona tiltable roll unit and which yieldably resiststilting of the unit inresponse to seivage departures, and means for adjusting the torque whilethe machine is in operation.

Still another object is to generally improve the structure and operativeeillciencyw of tiltable-roll selvage guiding structures as compared withprior selvage guider proposals.

-tailed description of one mechanism will It is, mereov'en'my intentionthat the patent shall cover, by suitable expression in the4appended'claims. whatever features of patentable novelty exist in theinvention disclosed.

In the accompanying drawings:

Figure 1 is a top plan view of a tiltable cloth guide mechanismembodying features of my invention;

Figure 2 is la side elevation of the mechanism of Figure 1 with portionsbroken away:

Figure 3 is an end elevation looking at the right hand end of themechanism of Figures l and 2:

Figure 4 is a cross-sectional view on line 4-4 of Figure 2;

Figure 5 is a front elevation-showing the Figures 1-4 form of myimproved cloth guiding units in their positions of maximum tilt, as whenno cloth is engaged between them; y

Figure 6 is a face view of a modied form of sewage-engaging wheel, itsshaft being shown in cross-section;

Figure 7 is a cross-sectional view on line 'I4-'i of Figure 6, on alarger scale;

Figure 8 is a view similar to Figure 1, but showing a modiiied-form'inwhich the peripherally 4mechanisms,r as seen 'in Fig. 5, are designed toserve respectively at the right` and left sides of the machine butotherwise will be substantially the same in structure and operation, anda debe equally applicable to the other.

Referringto Fig. 1,` each mechanism comprises a pair of rolls indicatedgenerally at l0 and I2 carried on a swinging arm I4 whose pivotal axisI6 is on a base I8 which is adapted for securement to a member 20 (Fig.5) which is adjustable on the bar 22 extending from side to side of themachine. The rolls I0, I2 are illustrated in an arrangement forco-action with a web which travels downward in a'vertical plane. If itbe desired that the web travel upwardor that. itapproach the guiderollsin a horizontal f plane orin anyv inclined plane between verticaland horizontal. the illustrated mechanism and co-acting elements wouldbe correspondingly shifted and altered for effective co-actionwith theweb, with suitable springs o r other mechanical means adjusted to act onthe tiltable unit in conjunction with or in absence of gravity as anyparticular embodiment may require.

In the embodiment herein represented, the axis I6 of the roll-carryingarm I4 is at right angles to the plane of travel of the web to therolls, and is located in rear of the rolls at a midlocation along theirextent and in the horizontal plane of the axes of the rolls. Arm. I4extends from its axis in general direction parallel with the plane ofthe web at the rear side of the latter and, at a location beyondtheouter ends of the rolls, the arm I4 turns sharply forward and has vtheforwardly extending part I4' on which the .rolls are mounted, the rollIIJ having a fixed axial support on arm extension I4' and the roll I2being. mounted in a bracket 2| toward the forward end of the extensionI4', for movement towardand from roll I8 about an axis 24 which f is'parallel with theaxls of roll lz and adjustable onitsblock bearing 26 bymeans o f set screw 28 andclalilping screws villi.- A coil spring 32holds lroll I2 resiliently in contact withroll Ill `or with; a web'ofcloth engaged between the rolls. SpringI 32 has one endanchored at 34 onarm I4 and has f its other end engaged around the headed end of a screw36 whichextends through anearv38 on bracket 2|, withy a wing nut 40 onthe threaded end of the` screw for adjusting the tension of .K

spring 32. ,e

Preferably, when the rolls are spread out of contact witheach other, theaxis of roll I2 will be slightly out of parallelism with the axis ofroll I0, with the inner unsupported end of roll I2 -a little closer toroll I0 than its supported end,

so that, when the rolls aredrawn together by spring 32, their inner endportions first contact each other, or a web of clothy engaged'betweenthem. If theroll axes initially were parallel, there would be a tendencyfor the rolls to engage at their outer supported endsand for their innerunsupported ends to be sprung a little away from each other, due to thehaving of a single support for each roll at its outer end. By having theroll I2 initially canted slightly toward roll IU, there is assurancethat the inner ends of the rolls will be in relation to effectively gripa web between them. Yet the outer end of roll I2 also is drawn by spring32 into gripping relation, possibly with a slight springing of thesupport, so that pressure betweenl the rolls approaches uniformitythroughout their lengths, or it may be that the pressure between therolls continuesto be a little greater at their inner un- Suliportedends.K

.Rolls I and I2 may be of any usual or desired construction but I'preferto employ rolls which V have surfaces of rubber or the like.

.According to my invention, a.A shaft 42l is mounted below the outerends of rolls I0, I2 and transversely of the rolls. In what I at present4 K i Y. 'consider to be a preferred form, as shown in Figs. 1-5,'theshaft is mounted in a frameY piece 44 which is secured as at 46 to thebase I8, whereby the frame piece 44 and the shaft remain xed in positionwhen-ann swings to tilt the rolls IIJ, l2. Frame piece v44 extends.outward generally parallel with the rolls at. the rear thereof and thenforwardly below the forward extension I4' shaft 42 extends and in whichthe shaft is /mounted. Each bearingl portion 48.156 has a ball-bearingunit 52 therein in which reduced ends of the shaft 42 are journalled, sothat the shaft is freely rotatable with a minimum of frictionalresistance. I

Adjacent the rear" ball-bearing unit 52, shaft 42 has the longitudinallyextending teeth V54 therein in mesh with the teeth 56' of a gear segment58 mounted on the roll-carrying arm 'I4 which itself is mounted onanti-friction ball-bearings as at 60, forswinging movement about itsaxis at I6 with a minimum of frictional resistance. r

Toward the forward end ofv shaft 42, a periphso that the wheel and shaftrotate as a unit. As

herein represented, the wheel comprises two dished sections clampedtogether on the threaded forward end of shaft 42 -by the clamping nuts64, 66 on opposite sides of the wheel. In the form as shown in Figs.y1-4, the peripheral groove 68 ln the wheel has substantial depth landhas slightly curved walls 'I0 asbest seen in Fig. 3.

Wheel 62 is located on shaft 42 with the center line of its groove 68precisely in the plane of the line of contact of the rolls I0 andl I2sothat'a selvage of a web o f cloth engaged between the rolls willengageedgewise .in `the wheel groove when said selvaglemoves laterallyoutward of the rolls a predetermined amount. Also, the wheel `62 and itsshaft 42 are located relative tothe desired' path of travel ofga selvageso that the selvage normally is within thel groove with the edge of theselvage spaced slightly from the bottom of the groove. Hence theselvagenormally is close enough to the groove vbottom so that only arelatively small outward departure of the selvage from its predeterminedcourse will cause it to frictionally engage the bottom of the wheelgroove 68 thereby to rotate the wheel and, through gear segment 58, tocause tilting of the rolls l0, I2 until the selvage moves out of contactwith the wheel groove.

my improved selvage guider is extremely sensitive to departures of aselvage and responds substantially instantaneously to eifect acorrection. The provision of ball-bearings at the journals of Iboth theswinging arm I4 and the wheel shaft 42 contributes to the sensitivityand eifectiveness and makes it practical and eliicient to ascomplishselvage control in response togedgewise engagement of the selvage withthe wheel 62. i In order to ensurethat an outward moving -selvage willengage in groove 68 of wheel 62, I provide the two guide rods 12, I4which are mounted as indicated generally at I6 on the frame into thewheel groove. The web engaging part of arm I4. 'Ihe forwardly projectingpart of the 10 frame piece 44 has a rear bearing portion 48 and aforward bearing portion 58 betweenvwhich the It is an important featureof the invention that piece 44, and project inwardly below the rolls I0,l2 to well beyond the periphery of wheel 62.

of guide rod 14 is above the web engaging part of rod 12, and projectstoward rod 12 a little beyond the plane of tne web, as best seen in Fig.3. This arrangement and shape ofthe guide rods tensions the selvagesomewhat to facilitate its entrance into the wheel groove 68.

Inasmuch as the surfaces of rolls I6, I2 preferally are of rubber, orthe like, wear at the roll surfaces may require adjustment of the wheel62 and of the guide rods 12, 14 so that they may be in proper relationsto the vertical plane in which the cloth or other web leaves rolls I6,I2. Wheel 82 is adjustable along its shaft 42 by means of its planewhere it would'be intersected by the 'pin to which the spring is -shownconnected if that clamping nuts 64, 6B which engage the threaded portion68 of the shaft. The guide rods 12, 14 are adjustable by reason of theirseeurement to a block 13 which is fadjustably clamped to frame piece 44by screws 16 passing through slot 11 in the frame piece.

The mechanism as herein illustrated has the center of gravity of thetiltable unit outward from its axis I6 so that, in Fig. 5, gravity tendsto rotate the unit at the left counter-clockwise and the unit at theright clockwise about axis I6. This tendency is counteracted by a coilspring 18 which has one end secured as at 80 to the rollcarrying arm i4and has its other end adjustably secured as at 92 to the fixed rod orbar 84 upstanding from the base I8. By adjusting the wing nut 86, thetension of spring 18 may be adjusted to attain anapproximate balancingof the tiltable unit with the rolls I0, I2 tilted at a desired angle.Ordinarily, in the mechanism herein disclosed, the tiltable unitinitially will be adjuste'd so that spring 16 will maintain the unitwith maximum tilt above the horizontal, such as at an angle oftwenty-five degrees to the horizontal. Then, when a. web of cloth isengaged, this angle is reduced until the rolls Waver only slightly aboveor below the horizontal, and the selvage normally runs just out ofcontact with the bottom of groqve 68 in wheel 62.

It is a feature df the invention that spring 18 has its point 90 ofsecurement roll-carrying arm I4 located in the plane of t e axes of therolls I0, I2, and relatively close to the axis I8 lof rotation of thetiltable roll unit, so that the spring tension effect on the tiltableroll unit is increased only slightly as the unit moves from its positionof balanced maximum tilt to its normal operating positions in which therolls may have relatively slight tilt, or none at all, relative to thehorizontal plane of the unit axis. It will be observed that theover-hung weight of the tiltable roll unit is such that gravity tends torotate the unit in one plane about the axis I6 and also tends to rotatethe unit in a vertical plane at right angles to the first'mentionedplane. Referring to Fig. 1, gravity not only tends to rotate the unitcounter-clockwise about shaft I6 but tends to rotate the unit indirection to cause the upper end of shaft I6 to move toward the `eye andthe lower end of shaft I6 to move away from the eye, thereby providingunequal distribution of the load on the bearings 60. An importantfeature of the invention is that the apparatus is designed so that thespring 18 applies torque to the tiltable unit which, in every positionof the unit equalizes or nearly equalizes the load on.the bearings 60.Referring to Figs. 1

and 8, the preferable location for connection of' spring 18 to thetiltable unit would be in the midst of the rolls I0, I2 in a planepassing through the center of gravity of the unit and parallel with theroll axes at a location in said pin could be extended. However, therolls Ill', I2 are in the way of such a preferred connection of spring18 to the unit and the connection, for best results, should be made asclose to roll I 9 as practicably possible, as shown in Fig. 8. Hence theunit tends to remain in a condition of approximate balance throughoutits range of movement and is more sensitively responsive to selvagedepartures than any prior comparable mechanism of which- I am aware.Alsothe having of the securement 88 of the spring to the unit in theplane of the roll axes makes the mechanism more readily adaptable todifferent conditions which may have to be met in particularinstallations. For example, referring to Fig. 5, the cloth guidingmechanisms as illustrated are suitable for guidingoselvages of a web ofcloth travelling vertically downward. If it is desired to have the webtravel vertically upward, the same selvage guidera may be employed buteach would be turned upside down and transposed so that each would be inthe place of the other. Also the bar 84 of each guider, and its spring18 would be shifted to extend above the reversed guiders, with thesprings acting against the tendency of gravity to tilt the inner ends ofthe rolls ing of the connection lof each spring 18 to theframe in theplane of the axes of the rolls greatly facilitates and simplies theadaptation `of the guider mechanisms for working on webs travelling indifferent locations. When these connec- .tions are located to one sideof the plane of the associated roll axes, as in prior` constructions.adaptation of a guider for working on an upwardtravelling web as abovesuggested has involved insertion of a link extension for each spring 18.

As herein represented. the spring 18 is a relatively strong coil spring.It should be underi stood, however, that the generally balancedcondition of the tiltable roll unit may be attained with a light springso long as itcan successfully counter-act the rotational eifect ofgravity on the unit.

Referring now to the modified form of selvageengaging wheel shown inFigs. 6 and 7, this wheel may be generally similar in construction tothe wheel. 62 of Figs. 1-4, but the groove walls are crimped orcorrugated as indicated generally at 88, so that a selvage 90 engagingbetween the corrugated walls 92, 94 is caused to assume va rippledshape. As shown in detail in Fig. 7, the` selvage comes more and moreinto frictional engagement with the corrugated walls 92, 94 as it movesinto the Wheel groove thereby to maintain the selvage taut andstabilized so that it more effectively and sensitively effects rotationof the wheel if and when it moves into frictional engagement with thebottom of the wheel groove.

Figs. 8 and 9 show a modification in which the selvage-engaging groovedwheel 62 is mounted on the tiltable roll unit and a gear segment 96 f isrelatively fixed and has internal teeth 98 for meshing with the toothedportion 54 of the -wheel shaft 42. In this case, a frame piece 44 mayhave bearing portions 48, 59 for shaft '42 as in the previouslydescribed form but the frame piece 44 has secured thereto, or formed asan integral part thereof, the bracket by which the frame piece and itsbearing portions 48, 50 may be rigidly mounted on the forward extensionI4' of 5 arm I4. Also, Figs. 8. and 9 show a preferred attachment of thespring 18 to the tiltable unit in that the attachment is effected at 80'inward of the bearings for the tiltable unit. This has the importanteiect of reducing substantially the friction at the bearings 60 due tothe over-hung weight of the tiltable unit because the spring tends tocounteract the overhung weight which otherwise tends strongly to tiltthe bearing shaft in a vertical plane.

The arrangement of the selvage guiding rods 12, 'I4' in Figs. 8 and 9 isconsidered to-be a preferred arrangement because thereois assurance thata selvage travelling outward between the guide rods must enter thegroove of wheel v62, whereas, with the rods spread as in Figs. 1 and 4,there may be a possibility that a selvage might escape the wheel grooveand become engaged between a guide rod and a wheel flange.

It will be obvious from the foregoing that I have provided an improvedselvage guider wherein a novel -control is attained by frictionalengagement of a selvage with roll-tilting mechanism which may or may notcontinue in its initial position regardless of the positions of theweb-engaging rolls and wherein a superior degree of sensitivity ofcontrol and general eciency are made possible, as compared with priorselvage guiders.

I claim as my invention: Y

l. In a web guiding machine, a pivoted unit having a pair of co-actingrolls for engaging opposite faces of a travelling web at a marginalregion of the web, rotatable means on an axis transverse of the axes ofsaid rolls and in the path of outward travel of said marginal region ofsaid travelling web and adapted to be rotatedy by frictional engagementof said outward travelling web therewith, and means responsive to arotation of said rotatable means for effecting a movement of saidpivoted unit about its pivot.

2. In a web guiding machine, a pivoted unit having a pair of co-actingrolls for engaging opposite faces of a travelling web at a marginalregion .of the web, means movable about an axis disposed generallytransversely of the axes of the rolls and in the path of outward travelof an edge of said travelling web and adapted to be rotated byengagement of the web therewith, and means responsive to a rotation ofsaid means and movable about an axis for swinging said unit about itspivot.

3. In a web guiding machine, a pivoted unit having a pair of co-actingrolls for engaging opposite faces of a travelling web ata marginal 60region of the web, a shaft mounted generally\ transversely of the axesof the rolls, means fixed on said shaft in the path of outward travel ofan edge of said travelling web and adapted to be moved about its axisthereby to rotate said shaft when frictionally engaged by` the web,leverage means, and means on said shaft co-acting with said leveragemeans to effect a rocking of said pivoted unit in response to rotationof said shaft.

fi. In a web guiding machine, a pivoted unit having a pair of co-actingrolls for engaging opposite faces of a travelling web at a marginalregion of the web, means at a xed location blocking the path of outwardtravel of an edge of said travelling web and movable at said xed 75 8location in response to engagement ofthe web therewith, and connectionsbetween said means and said pivoted unit for actuating said unit aboutits pivot in response to a movement of said means by the web.

5. A machine for guiding the selvage of a travelling web of cloth,comprising a pivoted unit including a pair of vcloth engaging rolls, arelatively xed support for said unit, means mounted on said supportindependently of said pivoted unit and standing rotatably at a xedlocation blocking the path of outward travel of a. selvage and rotatablein response to frictional engage-- ment of a said selvage therewith, andconnections between said means and said pivoted unit whereby a rotationof said means by a said selvage eifects a movement of said unit aboutits pivot thereby to tilt said rolls, and said means continuing in itsoriginal position during tilting of the rolls.

6. A machine for guiding the selvage of a travelling web of cloth,comprising a pivoted unit including a pair of cloth engaging rolls, a.

relatively ilxed support for said unit, a shaft mounted rotatablygenerally transversely of the axes of the rolls, a wheel xed on saidshaft and having a peripheral groove disposed in the path of outwardtravel of a selvage and adapted to receive a selvage edgewise therein,lanti-friction bearings for said shaft facilitating rotation of the shaftand wheel in response to frictional engagement of a travelling selvagewith the walls of the peripheral groove of said wheel, Iand coactingmeans respectively on said relatively xed support and said pivoted unitand including means adapted to rotate in unison with said wheel forrocking said unit inlresponse to rotation of said wheel.

7. Cloth guiding mechanism comprising a pair of rolls for engagingbetween them a marginal region of a travelling web of cloth, a pivotallymounted frame supporting the rolls and movable about its pivot fortilting the rolls in general parallelism with the plane of travel of theweb -between the rolls, pivoted means beyond the rolls therewith,` andconnections between said pivoted means and said pivotally mounted framefor effecting a tilting of said rolls in response to a said movement ofsaid pivoted means, and independently of drag of the web on said rolls.

8. Cloth guiding mechanism comprising a pivoted unit having a pair ofrolls for engaging between them. a selvage region of a'travelling web ofcloth, said unit being movable about its pivot to tilt saidrollsgenerally in parallelism with the plane of the web `travelling betweenthem and being designed so that gravity tends to rotate the unit in onedirection about its pivot, resilient means adjustably opposing saidrotational tendency due to gravity, rotatable means fixed in positionrelative to said pivoted unit and disposed adjacent 'to thepredetermined path of a travelling selvage blocking the way against anysubstantial lateral departure of the selvage from its said predeterminedpath and adapted to be rotated by frictional engagement therewith of asaid selvage departing from said predetermined path, and mechanicalconnections for moving said pivoted unit about its pivot in response toa rotation of said rotatable means, thereby' to tilt said rolls indirection to restore said selvage to its predetermined path of travel. l

9. Cloth guiding mechanism comprising a pivoted unit having a pair ofrolls for engaging between them a selvage region of a travelling web ofcloth, said unit being movable about its pivot to tilt said rollsgenerally in parallelism with the plane of the web travelling betweenthem and being designed so that gravity tends to rotate the unit in onedirection about its pivot, resilient means adjustably opposing saidrotational i tendency due to gravity, a shaft mounted rotatably with itsextent generally transverse of the roll axes, means fixed on the shaftand disposed adjacent to the predetermined pathof a selvage and adaptedto be engaged by a said selvage departing from said path thereby tocause rotation of said shaft, and inter-engaging means fixedrespectively on said shaft and on said pivoted unit whereby a rotationalmovement of said shaft is transmitted to said unit to tilt said rolls.

10. Cloth guiding mechanism comprising a pivoted unit having a pair ofrolls for engaging between them a selvage region of a travelling web ofcloth, said unit being movable about its pivot to tilt said rollsgenerally in parallelism with the plane of the web travelling betweenthem and' being designed so that gravity tends to rotate the unit in onedirection about its pivot, resilient means adjustably opposingsaid'rotational tendency due to gravity, a shaft mounted rotatably withits extent generally transverse of the roll axes, a peripherally groovedwheel fixed on the shaft and located with the bottom of` its grooveopposite and close to the'predetermined path of a selvage whereby adeparture of the selvage from said path bringslit into frictionalengagement with the bottom of said wheel groove thereby to' rotate thewheel, a gear on said shaft, and means on said pivoted unit`inter-engaged with said gear, whereby rotation of said shaft effects atilting of said rolls.

11. A web guiding machine comprising a pivoted unit having a pair ofco-acting rolls for engaging opposite faces of a travelling web at amarginal region of the web, means adjacent to the edge of said marginalregion of the web blocking the path of outward travel of an edge of theweb and responsive to frictional engagement of the web therewith forswinging said unit about its pivot, thereby to shift the axes of saidrolls relative to a, predetermined plane, said pivoted unit tending torotate in one direction about its pivot due to the force of gravity, andadjustable tension means acting on said pivoted unit in opposition tothe force of gravity thereon and adjusted' to place said unit in astateof approximate balance with the axes of said rolls in apredetermined plane.

l2. A web guiding machine comprising a pivoted unit having a frame and apair of co-acting rolls supported by the frame for engaging oppositefaces of a travelling web at a marginal region y pivot of said unit thanto the plane of the outer ends of said rolls, said location of theconnection.

of the spring to the unit frame being as close as practicably possibleto the adjacent roll and thus acting web-engaging rolls, said unittending to rotate in one plane about its pivot under the intluence ofgravity and tending by gravity to rotate in a second plane at rightangles to said first plane, e. coil spring acting on said unit inopposition to the influence of gravity thereon. said spring beingdesigned and connected to the unit so that it approximately balancessaid tendency of the unit to rotate in said second plane, therebytending to equalize the load on said spaced apart bearings, and meansfor adjusting the tension of said spring to place said unit in acondition of approximate balance when the axes of said rolls are in apredetermined plane.

14. Ina web-guiding machine having a pair oi' web-engaging rolls, aperipherally grooved wheel rotatably mounted for rotation about an axistransverse of the axes of said rolls and fixed relative to thepredetermined path of a marginal region of a travelling web, saidmarginal region of the web normally travelling out of contact withthe'walls of the groove of the wheel. and said wheel beingv rotatable inresponse to frictiona1 engagement of said marginal region of the webwith a wall of the wheel groove.

. 15. In a web-guiding machine, a peripherally grooved wheel rotatablyxed relative to the pre-v determined path of a marginal region of a.travelling web, the walls ofthe groove of the wheel being corrugated,and said marginal region of the web normally travelling out of contactwith said corrugated walls of the wheel groove, means for guiding saidmarginal region of the web into the wheel groove whereby said marginalregion `lof the web, upon outward departure from its predetermined path,engages the corrugated walls of the wheel groove whereby the selvage isconditioned for effective wheel-rotating frictional engagement in thebottom of the wheel groove, by being rendered-taut and stabilized as ittravels into the groove.

16. In a web-guidingl machine having a pivoted unit with co-actingweb-engaging rolls, said unit tending to rotate in one plane about itspivot under the influence of gravity and tending by gravity to rotate ina second plane at right angles to said first plane, a coil spring actingon said unit in opposition to the influence of gravity thereon, saidspring being designed and connected to the unit so that it approximatelybalances said tendency of the unit to rotate in said second plane andmeans for adjusting the tension of said spring while the machine is inoperation thereby to reduce the torque on said pivoted unit whilethemaximum torque during operation is eiective.` t

17. In a web-guiding machine having a pivoted unit f with co-acting`web-engaging rolls, means acting on said pivoted unit` and tending tomaintain it in a condition of approximate balance with the axes of saidrolls in a predetermined plane, a peripherally grooved wheel mountedrotatably on an axistransverse of the roll axes with its groove in thepath of outward travel of an edge of a web engaged between said rolls,said edge of web being adapted to fric- 11 tance, and means responsivetov rotation of said wheel for eiecting a predetermined tilting of saidpivoted unit thereby t0 modify the effect of said rolls on the web. f

18. In a webguiding machine having a pivoted unit with co-actingweb-engaging rolls, means acting on said pivoted unit and tending tomainand tending also to rotate the unit in'a vertical plane at rightangles to said pivotal axis, said means acting on the unit including atension coil spring connected to the unit beyond said bearings in thedirection of overhang of the unit and acting in opposition to saidover-hung weight, said spring being designed and connected to the unitso thatit approximately balances the rotational tendency of the unit insaid plane at right angles to said pivotal axis, thereby to reduce andequalize the load on said anti-friction bearings, and there being meansfor adjusting the tension oi' said spring to reduce the torque while themachine is in operation.

19. A web guiding machine comprising a pivoted unit having a pair ofco-acting rolls for engaging opposite faces of a travelling web at a'marginal region of the webg pair of bearings for said unit spaced apartalong the pivotal axis of the unit, said unit having its center ofgravity located a substantial distance outward from said bearings in thegeneral direction of extent of the I 35 Number pivotal axis of the unitand off-set substantially to one side of the plane of said pivotal axisof the A unit, whereby gravity tends to rotate the unit in one directionabout its pivotal axis and tends also to. rotate the unit about a secondaxis at right angles to said pivotal axis of the unit, and adjustabletension means acting on said unit in opposition to gravity and adaptedto counter-act the said tendency of gravity to rotate the unit ,aboutsaid second axis thereby to reduce and equalize the load 0n s'aid'pairof spaced apart bearings.

20. A 'web guiding machine `as in claim 19 wherein said adjustabletension means is a. coil spring having one end adjustably fixed inposition and having its other end connected to said unit approximatelyin the plane of the axes of said rolls and between the parallel planesof the pivotal axis of the unit and the center of gravity of the unit,said spring reducing and equalizing the load on said bearings.

21. A web guiding machine as in claim 19 wherein said adjustable tensionmeans is a coil spring having one end adjustably ixed in position andhaving its other end connected to said unit between the parallel planesof the unit axis and the center of gravity of the unit and also betweenparallel planes passing respectively through theicenter of gravity ofthe unit and through one of said bearings, the latter parallel f planesbeing at right angles to the first men- 4tioned parallel planes, saidspring applying torque to the unit to reduce load on the bearings.

JOHN D. ROBERTSON.

REFERENCES CITED The following references are of record in the le ofthis patent: Y

UNITED STATES PATENTS and equalize the Name Date 1,835,438 Sichert Dec.8, 1931 2,096,087 Coolidge Oct. 19, 1937 1,472,499 Smart et al Oct. 30,1923 1,995,462 Tandel Mar. 26, 1935 2,118,375 Dungler May 24, 19381,185,173 Bolton May 30, 1916

